England's chances of football success are in jeopardy, according to the man responsible for producing the next generation of talent.

Sir Trevor Brooking told BBC1's Inside Sport the rising number of foreign players in the top flight has led to a lack of depth in key areas for England.

The FA's director of development warned: "(The national team) has to be under threat - the numbers show that.

"I don't think you can underestimate it. It's a major concern."

In 10 years' time you don't want us just being pleased to qualify for tournaments

Sir Trevor Brooking

Brooking was speaking after a summer of record transfer spending by English clubs - much of it abroad - and before two must-win Euro 2008 qualifiers for Steve McClaren's under-fire England team.

Research by BBC Sport has revealed the extent of the challenges currently facing the national team as the pool of talent available to the manager decreases.

76% of the starting XIs that played on the first weekend of the first Premier League season in 1992 were English, only 37% were English on the first weekend of this season

Only 10% (23 players) of the starting XIs in 1992 were from outside the UK, this season that number had increased to 56% (123)

Non-English players have scored 69% of Premier League goals so far this season - they have even scored two of the three own goals

Of the 118 goals scored so far, only nine have been scored by seven English strikers

According to the latest Deloitte figures for disclosed transfer fees, spending by Premier League clubs rose from £333m in 2006 to £531m in 2007

Half of that went to non-English clubs

Brooking is under no doubt that the growing number of foreign players in the Premier League is depriving domestic talent of first-team football and that is having a detrimental effect on England's chances of challenging at major tournaments.

"Last year about 40% of starting XIs in the Premier League were English," the 58-year-old England and West Ham legend said.

"And with all the buying that has gone on over the summer that will probably fall to under a third. Will there be first-team opportunities for some of our youngsters between 17 and 21?

"If you look at Italy when they won the last World Cup, I think they had over 70% of their league made up of domestic players. Spain, France, Holland, they're all up there too. Germany aren't much better than us but we're the lowest.

"The more that goes down, and the pool of choice reduces, we must come under pressure. In 10 years' time you don't want us just being pleased to qualify for tournaments."

Brooking, who was speaking at an FA-backed coaching day in Romford for five to 11-year-olds, was particularly concerned about the dearth of attacking options open to McClaren for Saturday's game against Israel and next Wednesday's crucial encounter with Russia.

With inspirational forward Wayne Rooney and midfield goal threats David Beckham and Frank Lampard injured - and Peter Crouch suspended for the Israel game - England have been forced to call up Emile Heskey and Ashley Young to bolster a strike force that can hardly be called prolific.

The much-maligned Heskey has at least scored this season - a claim that cannot be made by fellow England forwards Jermain Defoe, Andrew Johnson, Alan Smith or Young. And only Michael Owen, who has just returned from a year out injured, can boast of a goal this season and an international pedigree.

We've got a good nucleus now but after that is there enough coming through?

Sir Trevor Brooking

"We have nowhere near the depth we should have and that will be an issue as soon as you pick up injuries," said Brooking, who made 47 appearances in England's midfield during a distinguished career.

"We have that now in attack with the senior squad and we're struggling to find a replacement."

But as well as highlighting the threat to England's hopes of success posed by the diminishing number of players to select from in the Premier League, Brooking acknowledged the quality of English players had to improve too.

"Creating and scoring goals will be the big challenge for the English game and that will not improve unless we focus on developing our players better," he said.

"Injuries, form and combinations play a big part but you would like to go to any tournament with a chance. OK, it's frustrating when you don't win but let's stay in the melting pot.

"We've got a good nucleus now - our squad in last year's World Cup was one of the youngest - so they should stay together for the next five years or so. But after that, is there enough coming through?"